N80: Endometriosis

Endometriosis is a medical condition where tissue similar to the lining of the uterus, known as endometrium, grows outside the uterus. This aberrant tissue can be found on the ovaries, fallopian tubes, and the tissue lining the pelvis. Rarely, endometrial tissue may spread beyond the pelvic region. Unlike the normal uterine lining, this displaced tissue has no way to exit the body and becomes trapped. When the ovaries are involved, cysts called endometriomas may form. Surrounding tissue can become irritated, eventually leading to scar tissue and adhesions. This may cause pelvic tissues and organs to stick to each other. The main symptoms are pain and menstrual irregularities. Endometriosis can sometimes cause infertility. The exact cause of endometriosis isn't clear, but possible explanations include retrograde menstruation, transformation of peritoneal cells, embryonic cell transformation, surgical scar implantation, and endometrial cells transport via the blood or lymphatic system.